1. Field of the Invention
The present invention relates to an image display apparatus and an image display method. To be specific, the present invention relates to an image display apparatus and an image display method for extracting data of a tubular structure from volume data acquired by imaging a subject including the tubular structure, generating an image of the inside of the tubular structure by surface rendering, and displaying the generated image of the inside of the tubular structure on a monitor.
2. Description of the Related Art
The abovementioned type of image display apparatus sets a viewpoint in a tubular structure at all times, moves the viewpoint in one direction from one end to the other end of the tubular structure, generates an image obtained by observing the inside of the tubular structure at the viewpoint toward the destination of the movement (in the one direction) at every movement position of the viewpoint, and stores the generated image into a storage. In response to designation of the viewpoint by an operation part, the image display apparatus reads out the image of the inside of the tubular structure in the one direction corresponding to the movement position of the viewpoint from the storage, and displays the read-out image on a monitor (Japanese Unexamined Patent Application Publication No. 2007-195685).
The abovementioned technique is called a virtualized endoscope system (VES). The VES is used in various clinical sites, for example, in a test on the large intestine. The image display apparatus described in JP-A 2007-195685 is the VES, which is a technique for displaying, on a monitor, an image obtained by observing the inside of a tubular structure from a viewpoint toward the destination of movement (in one direction).
However, there is a problem in use of the abovementioned technique (VES) for a test on the large intestine. Protrusions such as haustra exist inside a tubular structure, i.e., inside the large intestine.
When the inside of the tubular structure is observed at the viewpoint toward the destination of movement (in one direction), the protrusions create blind spots, which may make it impossible to easily find a lesion site or the like.